Uppercase vs. capitalized environment variable names during debug

Question

What could cause the following different behavior during a debug vs. launch session?

In eclipse-debug and maven-run I get all environment variables in uppercase while in eclipse-run some remain as defined in windows.

@Test
public void testEnvironmentVariables() {
    ArrayList<String> keys = new ArrayList<>(System.getenv().keySet());
    Collections.sort(keys);
    System.out.println(keys);
}

The output if executed by Run: notice http.proxyUser

[=::, ALLUSERSPROFILE, APPDATA, APR_ICONV_PATH, CLASSPATH, CLINK_DIR, COMPUTERNAME, ChocolateyBinRoot, ChocolateyInstall, ComSpec, CommonProgramFiles, CommonProgramFiles(x86), CommonProgramW6432, DEBUG_PORT, DEFLOGDIR, EC_COMPUTER_OU, EC_HOMEAPPDATA, EC_USER_DEPARTMENT, EC_USER_DG, EC_USER_DISPLAY_NAME, EC_USER_ELK, EC_USER_OU, EXTRA_JAVA_PROPERTIES, FP_NO_HOST_CHECK, GRADLE_HOME, HOMEDRIVE, HOMEPATH, JAVA_HOME, JAVA_OPTS, LDMS_LOCAL_DIR, LOCALAPPDATA, LOGONSERVER, LocalRunSetup, M2, M2_HOME, M2_REPO, MAVEN_OPTS, MW_HOME, NUMBER_OF_PROCESSORS, ORACLE_BASE, ORACLE_HOME, OS, PATH2, PATHEXT, PROCESSOR_ARCHITECTURE, PROCESSOR_IDENTIFIER, PROCESSOR_LEVEL, PROCESSOR_REVISION, PSModulePath, PUBLIC, Path, ProgramData, ProgramFiles, ProgramFiles(x86), ProgramW6432, SBT_HOME, SESSIONNAME, SFT_SOFTGRIDSERVER, SystemDrive, SystemRoot, TEMP, TMP, USERDNSDOMAIN, USERDOMAIN, USERDOMAIN_ROAMINGPROFILE, USERNAME, USERPROFILE, UUMDS_CFG, VAGRANT_HOME, VBOX_MSI_INSTALL_PATH, VSEDEFLOGDIR, chocolatey_bin_root, debugFlag, http.proxyHost, http.proxyPassword, http.proxyPort, http.proxyUser, http_proxy, https.proxyHost, https.proxyPassword, https.proxyPort, https.proxyUser, https_proxy, myProxy, no_proxy, uumds.config.location, windir, windows_tracing_flags, windows_tracing_logfile]

The output if executed by Debug: notice HTTP.PROXYUSER

[ALLUSERSPROFILE, APPDATA, APR_ICONV_PATH, CHOCOLATEYBINROOT, CHOCOLATEYINSTALL, CHOCOLATEY_BIN_ROOT, CLASSPATH, CLINK_DIR, COMMONPROGRAMFILES, COMMONPROGRAMFILES(X86), COMMONPROGRAMW6432, COMPUTERNAME, COMSPEC, DEBUGFLAG, DEBUG_PORT, DEFLOGDIR, EC_COMPUTER_OU, EC_HOMEAPPDATA, EC_USER_DEPARTMENT, EC_USER_DG, EC_USER_DISPLAY_NAME, EC_USER_ELK, EC_USER_OU, EXTRA_JAVA_PROPERTIES, FP_NO_HOST_CHECK, GRADLE_HOME, HOMEDRIVE, HOMEPATH, HTTP.PROXYHOST, HTTP.PROXYPASSWORD, HTTP.PROXYPORT, HTTP.PROXYUSER, HTTPS.PROXYHOST, HTTPS.PROXYPASSWORD, HTTPS.PROXYPORT, HTTPS.PROXYUSER, HTTPS_PROXY, HTTP_PROXY, JAVA_HOME, JAVA_OPTS, LDMS_LOCAL_DIR, LOCALAPPDATA, LOCALRUNSETUP, LOGONSERVER, M2, M2_HOME, M2_REPO, MAVEN_OPTS, MW_HOME, MYPROXY, NO_PROXY, NUMBER_OF_PROCESSORS, ORACLE_BASE, ORACLE_HOME, OS, PATH, PATH2, PATHEXT, PROCESSOR_ARCHITECTURE, PROCESSOR_IDENTIFIER, PROCESSOR_LEVEL, PROCESSOR_REVISION, PROGRAMDATA, PROGRAMFILES, PROGRAMFILES(X86), PROGRAMW6432, PROMPT, PSMODULEPATH, PUBLIC, SBT_HOME, SESSIONNAME, SFT_SOFTGRIDSERVER, SYSTEMDRIVE, SYSTEMROOT, TEMP, TMP, USERDNSDOMAIN, USERDOMAIN, USERDOMAIN_ROAMINGPROFILE, USERNAME, USERPROFILE, UUMDS.CONFIG.LOCATION, UUMDS_CFG, VAGRANT_HOME, VBOX_MSI_INSTALL_PATH, VSEDEFLOGDIR, WINDIR, WINDOWS_TRACING_FLAGS, WINDOWS_TRACING_LOGFILE]

If executed from maven: notice HTTP.PROXYUSER testEnvironment=[=::, =C:, =EXITCODE, ALLUSERSPROFILE, APPDATA, APR_ICONV_PATH, CHOCOLATEYBINROOT, CHOCOLATEYINSTALL, CHOCOLATEY_BIN_ROOT, CLASSPATH, CLASSWORLDS_JAR, CLASSWORLDS_LAUNCHER, CLINK_DIR, COMMANDER_DRIVE, COMMANDER_EXE, COMMANDER_INI, COMMANDER_PATH, COMMONPROGRAMFILES, COMMONPROGRAMFILES(X86), COMMONPROGRAMW6432, COMPUTERNAME, COMSPEC, DEBUGFLAG, DEBUG_PORT, DEFLOGDIR, EC_COMPUTER_OU, EC_HOMEAPPDATA, EC_USER_DEPARTMENT, EC_USER_DG, EC_USER_DISPLAY_NAME, EC_USER_ELK, EC_USER_OU, ERROR_CODE, EXEC_DIR, EXTRA_JAVA_PROPERTIES, FP_NO_HOST_CHECK, GRADLE_HOME, HOME, HOMEDRIVE, HOMEPATH, HTTP.PROXYHOST, HTTP.PROXYPASSWORD, HTTP.PROXYPORT, HTTP.PROXYUSER, HTTPS.PROXYHOST, HTTPS.PROXYPASSWORD, HTTPS.PROXYPORT, HTTPS.PROXYUSER, HTTPS_PROXY, HTTP_PROXY, JAVA_HOME, JAVA_OPTS, LDMS_LOCAL_DIR, LOCALAPPDATA, LOCALRUNSETUP, LOGONSERVER, M2, M2_HOME, M2_REPO, MAVEN_CMD_LINE_ARGS, MAVEN_JAVA_EXE, MAVEN_OPTS, MAVEN_PROJECTBASEDIR, MW_HOME, MYPROXY, NO_PROXY, NUMBER_OF_PROCESSORS, ORACLE_BASE, ORACLE_HOME, OS, PATH, PATH2, PATHEXT, PROCESSOR_ARCHITECTURE, PROCESSOR_IDENTIFIER, PROCESSOR_LEVEL, PROCESSOR_REVISION, PROGRAMDATA, PROGRAMFILES, PROGRAMFILES(X86), PROGRAMW6432, PROMPT, PSMODULEPATH, PUBLIC, SBT_HOME, SESSIONNAME, SFT_SOFTGRIDSERVER, SYSTEMDRIVE, SYSTEMROOT, TEMP, TMP, USERDNSDOMAIN, USERDOMAIN, USERDOMAIN_ROAMINGPROFILE, USERNAME, USERPROFILE, UUMDS.CONFIG.LOCATION, UUMDS_CFG, VAGRANT_HOME, VBOX_MSI_INSTALL_PATH, VSEDEFLOGDIR, WDIR, WINDIR, WINDOWS_TRACING_FLAGS, WINDOWS_TRACING_LOGFILE]

I found a similar question here: Uppercase vs. capitalized environment variable names during debug [message #242568], but without any answer.

I'm using Java 8 on Windows 7 and Eclipse v4.6 (Neon).

>java -version
java version "1.8.0_77"
Java(TM) SE Runtime Environment (build 1.8.0_77-b03)
Java HotSpot(TM) 64-Bit Server VM (build 25.77-b03, mixed mode)

Eclipse Java EE IDE for Web Developers
Version: Neon Release (4.6.0)
Build id: 20160613-1800

> mvn -version
Apache Maven 3.3.3 (7994120775791599e205a5524ec3e0dfe41d4a06; 2015-04-22T13:57:37+02:00)
Maven home: C:\costin\apps\apache-maven-3.3.3
Java version: 1.8.0_77, vendor: Oracle Corporation
Java home: C:\Program Files\Java\jdk1.8.0_77\jre
Default locale: en_GB, platform encoding: Cp1252
OS name: "windows 7", version: "6.1", arch: "amd64", family: "dos"

Answer 1

You are not debugging using JPDA. Using JPDA you see exactly the same HashMap used in System. You must be using two different VM executions because the order of the keys differs, this is not a 100% Java debugging.

In two different processes you can have different namings for the execution by using system-properties before environment-variables.